What turns rich nations into "great powers"? Why, as states grow increasingly wealthy, do they build large armies, entangle themselves in politics beyond their borders, and seek international influence? What factors speed or retard the translation of material resources into political interests? These questions, central to the theory and history of international relations as well as the world we live in today, guide this study of the rise of the United States. Throughout history, few events in international life have been as regular or as disruptive as the arrival of a new great power on the world scene. From the Peloponnesian War over two thousand years ago--caused, in Thucydides' famous words, by "the growth of Athenian power and the fear which this caused in Sparta"--to the rise of Germany in this century, almost every new addition to the ranks of the great powers has resulted in global instability and war. E. H. Carr correctly identified the "problem of peaceful change" as the central dilemma of international relations.

The strong are all the same, Michael Mandelbaum writes: "They expand. They send their soldiers, ships, and public and private agents abroad. They fight wars, guard borders, and administer territories and people of different languages, customs, and beliefs far from their own capitals. They exert influence on foreigners in a variety of ways.... The strong do to others what others cannot do to them." Over the course of history, states that have experienced significant growth in their material resources have relatively soon redefined and expanded their political interests abroad, measured by their increases in military spending, initiation of wars, acquisition of territory, posting of soldiers and diplomats, and participation in great-power decision-making. Paul Kennedy concludes that "there is a very clear connection between an individual Great Power's economic rise and fall and its growth and decline as an important military power (or world empire)." Consider the brief rise and fall of Sweden. At the start of the seventeenth century, Sweden was hardly a bright prospect for great powerdom. With a largely peasant population, little industry, few towns, and a barter economy, its economic foundation was extremely weak. But after significant foreign investment and internal reforms, Sweden's fortunes changed, and in a short time it became one of Europe's richest countries and the leading producer of iron and copper. This new wealth paved the way for a more powerful military and a more assertive diplomacy. By 1630, Gustavus Adolphus had eagerly joined the European political fray on behalf of the Protestant cause, and Sweden's tremendous military force was critical in checking Habsburg ambitions over the next twenty years. In subsequent decades, it acquired several trans-Baltic territories, intervened repeatedly in Poland, and dreamed of uniting Scandinavia under its throne. Then, over the next sixty years, Sweden's economic might declined, compared to that of the industrializing economies of western Europe, and correspondingly its role as a great European power dwindled.

Sweden is a clear example of a trend one can see among nearly all rising powers, from the Netherlands in the late sixteenth century to Britain in the late eighteenth century to Japan in the late nineteenth century. Prussia, for example, remained a second-rank power until its economic takeoff in the 1850s. Between 1830 and 1880, the German state's share of world manufacturing output climbed nearly 150 percent, while its two great continental rivals, France and the Habsburg Empire, saw rises of just 50 percent and 40 percent respectively. Germany's GNP doubled between 1840 and 1870, growing more than that of any other European state. Joined with the Prussian military revolution of the 1860s, this growth underlay the successful wars of German unification and the new Germany's triumph over France. After 1870 Germany, backed by its unparalleled industrial power and led by the adroit Bismarck, would dominate the European great-power system. Diplomats at the time noted that now all roads led to Berlin.

So common was this pattern that European statesmen viewed the state that did not turn its wealth into political influence as an anomaly. In the eighteenth century, they spoke in astonishment and scorn of "the Dutch disease, a malady that prevented a nation enjoying unequalled individual prosperity and commercial prowess from remaining a state of great influence and power." With greater wealth, a country could build a military and diplomatic apparatus capable of fulfilling its aims abroad; but its very aims, its perception of its needs and goals, all tended to expand with rising resources. As European statesmen raised under the great-power system understood so clearly, capabilities shape intentions.

In the second half of the nineteenth century, the United States was afflicted with the Dutch disease. While America emerged from the Civil War as a powerful industrial state, unquestionably one of the three or four richest nations in the world, its foreign policy was marked by a persistent reluctance to involve itself abroad. Many historians of the period have asked why America expanded in the 1890s. But for the political scientist, viewing the country's power and expansion in comparative perspective, the more puzzling question is why America did not expand more and sooner. The period 1865-1908, particularly before 1890, presents us with many instances in which the country's central decision-makers noticed and considered clear opportunities to expand American influence abroad and rejected them. Certainly, between the time when they get rich and when they acquire expansive political interests abroad, countries often experience a time lag, frequently because policymakers fail to perceive the shift in their country's relative economic position. But America's central decision-makers were well aware of its economic strength and proudly proclaimed it. Nevertheless, the country hewed to a relatively isolationist line, with few exceptions, until the 1890s--a highly unusual gap between power and interests, for it lasted some thirty years. The United States would thus seem to represent an exception to the historical record and a challenge to the greatpower rule. (Before proceeding any further, I should note that historians of American foreign policy sometimes restrict the meaning of the term expansion to the acquisition of colonial territories. This study employs a broader, more commonsensical definition of the term; expansion can certainly involve imperialism, but it more generally refers to an activist foreign policy that ranges from attention to international events to increases in diplomatic legations to participation in great-power diplomacy. The Soviet Union, by this definition, could be called expansionist in the 1970s even though it was not formally annexing parts of Africa and Central Asia. Using territorial annexation as one measure of expansionism, the thirty years from 1865 to 1896 still stand out as an anomaly in American history.)

This study offers an explanation for this apparent aberration that is rooted in a more general theory of foreign policy. The search for a dominant cause that explains the course of late-nineteenth-century American foreign policy may seem misguided. Historians' accounts of the cases of expansion and nonexpansion stress different factors in each case, ranging from the balance of power to the influence of various interest groups to ideology--racism or social Darwinism or manifest destiny--to the idiosyncrasies of America's leaders. Such a complete account would, no doubt, be more accurate than either of this study's two contending theories of foreign policy, which rely on just one or two of these factors. But a list of facts and factors cannot explain the general dynamic motivating foreign policy that would result in nonexpansion in the 1870s and 1880s and yet expansion in the 1890s. William Henry Seward, secretary of state between 1861 and 1869, possessed as expansionist an ideology as did William McKinley and Theodore Roosevelt, and all three were equally aware of the relationship between power and interests. Why did the latter two succeed where the former failed? Some historians maintain that the expansion of the 1890s was prompted in large part by the depression of 1893 and the widespread sense that the country needed to expand to gain access to larger export markets, yet those same historians point to the economic troubles of the 1870s as preventing expansion in that era; if hard times can explain both expansion and isolation, how central can that factor be? The aim here is to tease out a plausible explanation for both expansion and nonexpansion, and for that we need a first-cut theory, not a full historical account.

TWO FIRST-CUT THEORIES

The literature on international relations offers two first-cut answers to the central question of this study: under what conditions do states expand their political interests abroad? These two theories of foreign policy, which explain national behavior--the attempt at expansion, not its success--are classical realism and defensive realism. Both start with the logic that the international system presents states with powerful constraints and opportunities that they cannot easily ignore, but they make radically different fundamental assumptions. Classical realism supposes that a nation's interests are determined by its power (meaning its material resources) relative to other nations: nations thus expand when they can. They do not expand in a mad frenzy--anywhere, anytime--but in a rational manner, it, places and at times that minimize costs and risks, in areas that are weaker than they, and when their power is on the rise. As Robert Gilpin argues, all states seek control over at least territory, the behavior of other states, and the world economy; the difference is that only rich states can act on these preferences. Scholars as diverse as Gilpin, Kennedy, Glenn Snyder, Bruce Bueno de Mesquita, and Aaron Friedberg--as well as traditional realists like Hans Morgenthau and E. H. Carr--all adopt some version of this theory in their work.

But classical realism's emphasis on national power as the most important factor affecting a nation's foreign policy overlooks an important distinction. Foreign policy is made not by the nation as a whole but by its government; consequently, what matters is state power, not national power. State power is that portion of national power the government can extract for its purposes and reflects the ease with which central decision-makers can achieve their ends. This variation on classical realism, which I call state-centered realism, maintains the logic that capabilities shape intentions, but it recognizes that state structure limits the availability of national power. Thus the structure, scope, and capacity of the state are crucial factors in explaining the process by which nations become increasingly active on the world stage. While models of how state structures can affect national policy have long been advanced by scholars of comparative politics--from Alexis de Tocqueville and James Bryce to Samuel Huntington and Theda Skocpol--the connection between the structure of the state and foreign policy has not been explored sufficiently. Domestic causes have often been regarded as competing with international pressures as explanations of foreign policy. This study demonstrates that a domestic variable, state power, can be introduced into a systemic theory without undermining the theory's basic premises. In fact, the logic of realism fits nicely with an appreciation of state structure. States may be billiard balls, but each is made of a different material, affecting its speed, spin, and bounce on the international plane.

The second theory of foreign policy, defensive realism presents a more benign view of the pressures of the international system. It posits that states seek security rather than influence and so predicts that nations expand their interests abroad when threatened. They expand in times of insecurity, against powerful nations with aggressive intentions. Absent a threatening environment, states have no systemic incentive to expand: they expand not when they can but when they must. Stephen Walt, Stephen Van Evera, and Jack Snyder--and before them, John Herz--are the most prominent exponents of this variant of realism.

However, this study shows why defensive realism's emphasis on threats is theoretically unhelpful. The concept of threat is highly malleable, and statesmen, rather than acknowledge their desires for influence and even hegemony, understandably often manufacture, consciously or unconsciously, "threats" and "dangers to security" to justify expansion. When statesmen cry "national security" to defend obviously aggressive behavior, this explanation for expansion becomes meaningless. More important still, defensive realism explains very little actual foreign policy. The international system, according to defensive realism, pushes states toward minimalist foreign policies. But since most great powers have been expansionist, they all must be considered exceptions to the rule. Great-power behavior is seen largely as abnormal and thus pathological, the result of domestic deformities. Defensive realists believe that states know from history that expansion is pointless: states balance against you rather than jump on your bandwagon, defense is often stronger than offense, and so on. Maybe, but the lessons of history are not scientific truths. Perhaps the defensive realists are right that states should glean certain lessons, but do they? Good theory explains how the world works, not how it should work.

This study tests these two theories of foreign policy by examining American attempts to expand its influence abroad in the late nineteenth century. Did the United States expand to counter threats, as defensive realism would predict, or to promote its influence, narrowing the gap between state power and foreign political interests, as state-centered realism would contend? Did the United States expand to balance against strong nations, which posed significant threats to its security. or did it expand in the direction of least resistance? And, equally important, when the United States did not expand, was it because of a benign international environment, the perception that security was "plentiful," or rather because America's weak state structure left its statesmen without access to its national potential?

THE HISTORICAL RECORD

The pattern of American foreign policy from the end of the Civil War to the close of Theodore Roosevelt's term as president largely confirms the predictions of state-centered realism: central decision-makers, which in the American case means the president and his closest advisers, expanded American influence abroad when they perceived increases in state power. The decades after the Civil War saw the beginning of a long period of growth in America's material resources. But this national power lay dormant beneath a weak state, one that was decentralized, diffuse, and divided. The presidents and their secretaries of state tried repeatedly to convert the nation's rising power into influence abroad, but they presided over a federal state structure and a tiny bureaucracy that could not get men or money from the state governments or from society at large. The president also had to contend with a state that impaired his ability to translate his administration's preferences into national policy; Congress could, and often did, prevent him from exercising his will. It refused to enact civil service and military reform, and the Senate rejected several annexation projects the executive branch had proposed. During this period, the power of the presidency was at a historic low: Andrew Johnson was impeached for daring to fire his secretary of war without congressional approval. Also, the unprecedented national debt after the Civil War fostered a pervasive sense of national bankruptcy and weakness that exacerbated this tension. America was an unusual great power--a strong nation but a weak state.

The 1880s and 1890s mark the beginnings of the modern American state, which emerged primarily to cope with the domestic pressures generated by industrialization. The exigencies of the growing national economy and the collapse of the congressional bid for supremacy gave the federal government a more centralized, less political, and rational structure. And as the only nationally elected officer of government, the president emerged with strengthened authority. This transformation of state structure complemented the continuing growth of national power, and by the mid-1890s the executive branch was able to bypass Congress or coerce it into expanding American interests abroad. America's resounding victory in the Spanish-American War crystallized the perception of increasing American power both at home and abroad. In keeping with the work of Robert Jervis and Aaron Friedberg, this study confirms that statesmen's perceptions of national power shift suddenly, rather than incrementally, and are shaped more by crises and galvanizing events like wars than by statistical measures. Having defeated a European great power in battle, America expanded dramatically in the years that followed, and several goals that had been under contemplation for decades--the annexation of Hawaii and Samoa, for example--became reality within months. At the moment of its greatest strength and security, having driven Spain out of the Western Hemisphere and with only an accommodating Britain as a European presence in the Americas, the United States chose to fill the resulting vacuum by expanding its influence. Because of its now-recognized status as a great power, actual threats to American security decreased from then on, and this greater security bred greater activism and expansionism. When confronted by real threats, as it occasionally was both before and after 1898, the United States usually opted to contract its interests, rather than expand to counter the enemy as defensive realism would forecast.

With the birth of the modern presidency under William McKinley came a symbiotic relationship between national executive power and foreign policy activism that has continued throughout the twentieth century. Theodore Roosevelt exploited the powers McKinley created and developed new ones as well, such as the routine use of executive agreements instead of treaties. The Progressive Era further strengthened the American state--again primarily for domestic reasons--and the great beneficiaries of this new authority were the national government and the president. Long a believer in congressional government, Woodrow Wilson became a particularly expansionist and unilateralist chief executive in matters of foreign policy.

PAST AND PRESENT

The causes of American expansion are not merely of theoretical or historical interest. As we look at the world today, the rise of new great powers is sure to cause ripples and repercussions across the globe. And the questions people ask about the new powers are the very ones we look at in this book. Upon the reunification of Germany in 1990, Lord Shawcross, an eminent British politician and jurist, warned that Europe might again be thrown into tumult if the Germans "use political power, commensurate with their economic strength. At the other end of the world, the rise of Japanese economic might has created an entire subfield of specialists and policy analysts who debate whether Tokyo is getting rich in order that it get strong or will break the mold, remaining nothing more than a "global civilian power." The chief reason that China's rise seems threatening to so many is that it appears to be taking a thoroughly traditional course, expanding its power and interests in tandem.

It is a truism that in the long run, increasingly wealthy nations will have increasing worldwide influence. But the nature of their rise, the time frame in which it occurs, the areas and issues that become flash points--all these specific matters remain uncertain, and the specifics will determine the course of international relations for the next century. Properly understood and properly handled, great power transitions can be smooth. Misconstrued and mismanaged, they can have cataclysmic consequences.